In general, hair dryers, also called “blow dryers” are well known. Typical handheld hair dryers blow ambient air or heated air over damp hair to accelerate the evaporation of water particles, thereby drying the hair more quickly than it would dry on its own. Typical hair dryers are powered by electricity from the power grid, that is, they are almost always plugged into a wall socket to get power. Typical hair dryers include two key components: a fan and a heating element downstream from the fan that selectively heats air as it is blown past by the fan. The first handheld, household hair dryers were introduced in the first half of the 20th century, and have only changed slightly in almost 100 years.
Hair dryer performance can be measured a number of different ways, but the most common measurements include air flow rate, velocity of the air as it leaves the hair dryer, and how much the air temperature increases relative to the ambient air temperature.
Existing hair dryers include a fan and at least one electric heating coil. The electric heating coils generate heat through the process of resistive heating. Electric current passing through the heating element is resisted by a coil of wire that results in the generation of heat. Resistance heating elements are typically made of wire or ribbon that may be straight, coiled, or formed into any other suitable shape. Resistive heating elements demand large amounts of electric current to generate heat sufficient to dry hair. As a result, hair dryers that use resistive heating elements have historically not been well suited to be powered by batteries.
Typical hair dryers also include switches that allow a user to control basic functions of the hair dryer. For example, typical hair dryers may include “hi” “low” and “off” settings for heat, and a “hi” and “low” setting for the fan. The aforementioned basic settings are adequate for hair dryers that draw electricity from the power grid, and until now there has been little motivation to better optimize performance of the hair dryer from the perspective of maintaining battery charge.
Until now, batteries capable of generating sufficient power (voltage×current) for a sufficient period of time to enable reliable hair drying performance have been prohibitively heavy, large, and expensive. Meanwhile, existing hair dryers, although lightweight, suffer from being tethered to a power outlet. Furthermore, a user drying their hair must move the hair dryer continuously around their head, and the power cord is often a nuisance.
As such, there is a need for a battery operated hair dryer that includes a battery management system to allow the hair dryer to efficiently dry hair while maintaining a maximum battery charge in a lightweight, inexpensive package.